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1.
The purpose of this double-blind study was to investigate the influence of exercise on the FA profile of the nonesterified
FA (NEFA) and phospholipid fractions in plasma of sedentary women supplemented with n−3 FA vs. women supplemented with oil
containing no n−3 FA. Twenty sedentary, premenopausal women were randomly assigned to receive 12 capsules daily of either
fish oil (3.5 g FPA and 2.4 g DHA per day, each as the ethyl ester) or evening primrose oil capsules (no detectable EPA or
DHA). Each subject consumed the capsules for one menstrual cycle. At the end of the supplementation period, the sedentary
subjects underwent an acute exercise trial [55% maximal oxygen consumption (VO2 max), 45 min] on a cycle ergometer. Two subjects in the fish oil group were removed from all calculations owing to noncompliance
for reasons not related to side effects. There were no changes in the phospholipid composition of either group of women after
exercise. In both control and fish oil-supplemented women, NEFA levels in general rose after exercise. There were no changes
in the percentage of any given individual NEFA in either supplementation group. However, absolute levels of certain individual
NEFA (16∶0, 18∶0, 18∶1, and 18∶3n−3) increased with exercise. Women supplemented with fish oil had increased levels of n−3
NEFA [EPA, DHA, and docosapentaenoic acid (DPA)] prior to exercise. Exercise did not, however, increase the absolute levels
of n−3 NEFA in the blood. 相似文献
2.
The effects of tricaine methanesulfonate (MS-222), a commonly used fish anesthetic, on plasma nonesterified fatty acid levels
(NEFA) were examined in rainbow trout,Oncorhynchus mykiss. Total NEFA levels declined with increasing duration of exposure to MS-222. Most of the decline in total NEFA was due to
decreases in saturated fatty acids (14∶0, 16∶0 and 18∶0). The fatty acid displaying the most rapid response to exposure to
MS-222 was 20∶5n−3. The lower plasma NEFA levels in anesthetized fish may be explained by depressed lipolysis in the presence
of the anesthetic. 相似文献
3.
The activity of the overt form of rat liver mitochondrial carnitine palmitoyltrasferase or CPT0 (EC 2.3.1.21) towards different fatty acid substrates was studied. The following non-esterified fatty acids (NEFA) and their
CoA esters in the presence of 1% bovine serum albumin (BSA) were tested: 16∶0, 18∶0, 18∶1, 18∶2, 18∶3ω3, 20∶4, 20∶5ω3 and
22∶6ω3. The data fit a square hyperbolic model for enzyme catalysis (p<0.001, non-linear regression). Asymptotic Vmax and K0.5, substrate concentration at one-half Vmax, were calculated using total concentrations of acyl-CoA, or unbound concentrations of NEFA. BSA was found to act as a true
substrate reservoir for NEFA in that the dissociation of the NEFA-BSA complex was 10–330 times faster than the CPT0 reaction. Regardless of form (NEFA or CoA ester), 18∶3ω3 gave the highest, while 22∶6ω3 and 18∶0 gave the lowest rates of
acylcarnitine synthesis. Except for 18∶3ω3 and 18∶2, Vmax for NEFA was generally lower than for acyl-CoA, with the greates differences observed for 20∶4, 20∶5ω3 and 22∶6ω3, suggesting
that acyl-CoA synthesis may also be important in the control of the entry of these fatty acids into the mitochondria. The
data provide an enzymatic rationale for the relatively low content of 18∶3ω3 in esterified lipid. 相似文献
4.
The fatty acid composition of individual phospholipids in subcellular fractions of sheep platelets and the asymmetrical distribution
of phosphatidylethanolamine (PE) fatty acyl chains across the plasma membrane were examined. The main fatty acids of total
lipid extracts were oleic (18∶1; 32–41%), linoleic (18∶2, 10–17%), stearic (18∶0; 13–15%), palmitic (16∶0; 11–15%) and arachidonic
(20∶4; 8–12%) acids, with a saturated/unsaturated ratio of about 0.4. Each phospholipid class had a distinct fatty acid pattern.
Sphingomyelin (SM) showed the highest degree of saturation (50%), with large proportions of behenic (22∶0), 18∶0 and 16∶0
acids. The main fatty acid in PE, phosphatidylserine (PS) and phosphatidylcholine (PC) was 18∶1n−9. Our findings suggest that
fatty acids are asymmetrically distributed between thecholineversus the non-choline phospholipids, and also between plasma membranes and intracellular membranes. The transbilayer distribution
of PE fatty acids in plasma membranes from non-stimulated sheep platelets was investigated using trinitrobenzenesulfonic acid
(TNBS). A significant degree of asymmetry was found, which is a new observation in a non-polar cell. The PE molecules from
the inner monolayer contained higher amounts of 18∶2 and significantly less 18∶1 and 20∶5 than those found in the outer monolayer,
although no major differences were detected in the transbilayer distribution of total unsaturatedversus saturated PE acyl chains. 相似文献
5.
The objective of this study was to test the effect of a novel fatty acid mixture, enriched with myristoleic and palmitoleic
acids, on plasma lipoprotein cholesterol concentrations. Weanling pigs were assigned to one of six groups and each group received
a diet differing in fatty acid composition. Diets were fed for 35 days and contained 10 g added cornstarch/100 g (to provide
baseline data) or 10 g added fatty acids/100 g. For those diets containing added fatty acids, extracted lipids contained 36%
myristoleic plus palmitoleic acid combined (14∶1/16∶1 diet), 52% palmitic acid (16∶0 diet), 51% stearic acid (18∶0 diet),
47% oleic acid (18∶1 diet), or 38% linoleic acid (18∶2 diet). Witht the exception of the cornstarch diet, all diets contained
approximately 30% myristic acid. There were no significant differences in weight gain across treatment groups (P=0.22). All diets caused a significant increase in triglycerides and in total, low density lipoprotein, high density lipoprotein,
and very low density lipoprotein cholesterol. The increase in total plasma cholesterol from pretreatment values was greatest
in pigs fed the 14∶1/16∶1 and 18∶1 diets. However, the increase in low density lipoprotein cholesterol from the pretreatment
concentration was greatest in the 14∶1/16∶1-fed pigs. Increases in very low density lipoprotein cholesterol above pretreatment
concentrations were lowest in 16∶0-fed pigs and greatest in 18∶1-fed pigs. Dietary fatty acids elicited changes in plasma
fatty acids which generally were reflective of the diets, although the 18∶0 diet did not alter plasma fatty acid concentrations
and the 16∶0 diet increased plasma 16∶0 only at the end of the study. These results demonstrated that the combination of myristoleic
plus palmitoleic acids increased plasma cholesterol in young pigs, suggesting that fatty acid chain length, rather than degree
of unsaturation, is primarily responsible for the effects of fatty acids on circulating lipoprotein cholesterol concentrations. 相似文献
6.
Yu-Yan Yeh 《Lipids》1988,23(12):1114-1118
A restricted maternal dietary intake (40% of ad libitum intake) is known to cause myelin deficit that is accompanied by decreased
amounts of individual phospholipids and sphingolipids in brain myelin of suckling rats. This communication reports the effects
of the same nutritional stress on the fatty acid composition of brain myelin lipids. In myelin of 19-day-old normally fed
rats, palmitate (16∶0), stearate (18∶0) and oleate (18∶1) accounted for 80–90% of all fatty acids in phosphatidylcholine,
phosphatidylethanolamine and phosphatidylserine. Maternal dietary restriction resulted in deficits of total fatty acid content,
but did not affect the proportional distribution of individual fatty acids among phospholipids. By contrast, longer chain
(22- and 24-carbon) fatty acids accounted for more than half the fatty acid content of myelin cerebroside and sulfatide from
the 19-day-old control rat pups. In undernourished rats of that age, proportions of lignocerate (24∶0) and nervonate (24∶1)
in cerebroside and sulfatide were 40–50% lower than those in control rats. This, together with higher proportions of 16∶0,
18∶0 and 18∶1 and a higher ratio of C16−C20 to C22−C24 in under-nourished than in control rats, suggests an impairment in fatty acid chain elongation. Ten days of nutritional rehabilitation
failed to restore the fatty acid imbalances; however, after an additional 5 days of ad libitum feeding, the experimental and
control values were similar. The undernutrition results in hypomyelination, which is characterized by a proportional decrease
in lignoceric and nervonic acids of sphingolipids. 相似文献
7.
Two unusual lipid classes were detected by thin-layer chromatography in the neutral lipids derived from goat cauda-epididymal
sperm plasma membrane. The lipids were identified as wax esters and 1-O-alkyl-2,3-diacylglycerols based on chromatographic properties, identity of their hydrolysis products, and infrared/1H nuclear magnetic resonance spectral evidence. The membrane containedca. 3 and 5 μg/mg protein of wax esters and alkyldiacylglycerols, respectively. The relative proportions of wax esters and alkyldiacylglycerols
in the total neutral lipids were 1.5% and 2.4%, respectively. The lipids contained fatty acids with chain lengths of C14 to C22. The major fatty acids of the wax esters were 14∶0, 16∶0, 16∶1ω7, 18∶0 and 18∶1ω9. The fatty acids in alkyldiacylglycerol
were 16∶0, 18∶0, 22∶5ω3 and 22∶6ω3. Alkyldiacylglycerol was particularly rich in docosahexaenoic acid 22∶6ω3) representing
30% of the total fatty acids. The alcohols of wax ester were all saturated with C20–C29 carbon chains. The deacylated products derived from alkyldiacylglycerols were identified as hexadecyl, octadecyl and octadec-9′-enyl
glycerol ethers. 相似文献
8.
The unsaponifiable lipids and total fatty acids of a nonphotosynthetic diatom,Nitzschia alba, have been examined. The major fatty acids were found to be 14∶0, 16∶0, 18∶1, and 20∶5; small amounts of 15∶0, 16∶1, 18∶0,
18∶2, 18∶3, and 20∶4 acids also were present. The unsaponifiable lipids consisted mostly of sterols, with only traces (<0.1%)
of hydrocarbons (chiefly C16, C18, and C28 normal olefins). The sterols contained brassicasterol (major) and clionasterol (minor), as well as traces of an unidentified
sterol; clionasterol was present only in glycosidically bound form. 相似文献
9.
The total lipids and fatty acid composition ofEntomophthora coronata were determined. The fungus was grown on a chemically defined medium and a chemically nondefined medium (Sabouraud dextrose
yeast extract) for a period of 26 days. The organism contained from 16.2% to 44.6% total lipids depending upon the days of
growth. The major fatty acids were 12∶0 (5.5–9.0%), 13∶0 (1.2–8.2%), 14∶0 (33.5–43.5%), 16∶0 (9.7–13.9%), 18∶19 (20.4–22.4%), and 18∶29,12 (3.5–10.5%). Lesser amounts of 15∶0, 16∶1, 16∶2, 17∶0, 18∶0, two other 18∶2 (both having conjugated double bonds), 18∶36,9,12, another 18∶3 (conjugated double bonds), 20∶38,11,14, 20∶45,8,11,14, another 20∶4 (conjugated double bonds), and 24∶1 acids were found. Trace amounts of 20∶0, 20∶1, 20∶2, 22∶0 and 24∶0 were
also present. The relative percentage of most of the fatty acids did not vary appreciably with growth. However, 18∶29,12 and 20∶45,8,11,14 increased with age of the chemically defined culture. Peak E (18∶2, conjugated double bonds) increased and 13∶0 and 18∶36,9,12 decreased with age of the chemically nondefined culture. The fatty acids were predominately saturated (56.9–69.1%) and contained
a high percentage of shorter chain fatty acids (C 12 to C 15). The fatty acids of the chemically defined culture were more
unsaturated than the Sabouraud culture and the unsaturation increased with age of the culture. 相似文献
10.
The lipid composition of the pineal organ from the rainbow trout (Oncorhynchus mykiss) was determined to establish whether the involvement of this organ in the control of circadian rhythms is reflected by specific
adaptations of lipid composition. Lipid comprised 4.9% of the tissue wet weight and triacylglycerols were the major lipid
class present (47% of total lipid). Phosphatidylcholine (PC) was the principal polar lipid, and smaller proportions of other
phospholipids and cholesterol were also present. Plasmalogens contributed 11% of the ethanolamine glycerophospholipids (EGP).
No cerebrosides were detected. The fatty acid composition of triacylglycerols was generally similar to that of total lipids
in which saturated, monounsaturated and polyunsaturated fatty acids (PUFA) were present in almost equal proportions. Each
of the polar lipid classes had a specific fatty acid composition. With the exception of phosphatidylinositol (PI), in which
20∶4n−6 comprised 27.4% of the total fatty acids, 22∶6n−3 was the principal PUFA in all lipid classes. The proportion of 20∶5n−3
never exceeded 6.0% of the fatty acids in any lipid class. The predominant molecular species of PC were 16∶0/22∶6n−3 and 16∶0/18∶1,
which accounted for 33.2 and 28.5%, respectively, of the total molecular species of this phospholipid. Phosphatidylethanolamine
(PE) contained the highest level of di-22∶6n−3 (13.0%) of any phospholipid. There was also 4.9% of this molecular species
in phosphatidylserine (PS) and 4.1% in PC. In PE, the species 16∶0/22∶6, 18∶1/22∶6 and 18∶0/22∶6 totalled 45.1%, while in
PS 18∶0/22∶6 accounted for 43.9% of the total molecular species. The most abundant molecular species of PI was 18∶0/20∶4n−6
(37.8%). The lipid composition of the pineal organ of trout, and particularly the molecular species composition of PI, is
more similar to the composition of the retina than that of the brain.
Molecular species are abbreviated as follows: e.g., 16∶0/22∶6 PC is 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine. 相似文献
11.
The fatty acid composition and distribution in egg yolk triglycerides and phosphatides from the turkey, duck, prairie chicken,
bobwhite quail, Japanese quail, and inbred-hybrid and midget mutant hens were determined after all species had been fed diets
of similar fat and fatty acid content for 90 days. Total volk lipids were composed of ca. two-thirds neutral lipids and one-third
polar lipids. The predominant fatty acids were palmitic and stearic. There were statistically significant differences in the
my ristic, palmitic, palmitoleic, linoleic, and linolenic acids in the yolk triglycerides and in the proportion of 16∶1, 18∶0,
18∶2, arachidonic, docosanoic, docosahexaenoic, and tetracosanoic acids in the phosphatides among the various species. Linoleic
acid predominantly was linked at the 2-position in the yolk triglycerides followed by the 20∶4 acid. The 18∶1 acid also was
found preferentially at the 2-position. There was a low level of 18∶2 in the yolk triglycerides and phosphatides from the
duck and an especially high level of 20∶4 acid in the phosphatides. The triglycerides in the species studied have essentially
the same distribution of fatty acids in the 2-position. In all the species, the affinity for the fatty acids at the 2-position
is in the following order: 18∶2=20∶4>18∶1 =18∶3>18∶0=16∶1>14∶0>16∶0 Differences observed among the various genera did not
appear to follow taxonomic boundaries. The duck has an efficient system for converting 18∶2 into 20∶4 by elongation and desaturation.
The prairie chicken apparently has a high requirement for 18∶2 but an inadequate system for its conversion into 20∶4. 相似文献
12.
F. Molaparast-Saless E. Shrago T. L. Spennetta S. Donatello L. M. Kneeland S. H. Nellis A. J. Liedtke 《Lipids》1988,23(5):490-492
A method has been developed for determination of individual long-chain fatty acyl-CoA esters from heart and skeletal muscle
using high performance liquid chromatography (HPLC). The esters were extracted from freezeclamped tissue of pig and rat hearts
and rat skeletal muscle for analysis on a radially compressed C18 5μ reversephase column. Nine peaks in the extract with carbon chain lengths from C12 to C20 that subsequently disappeared on alkaline hydrolysis were identified. The major acyl-CoA peaks were 14∶1, 18∶2, 16∶0 and
18∶1 and additionally in rat heart 18∶0. Total long-chain acyl-CoA esters obtained by summation of the individual molecular
species was 11.34±1.48 nmol/g wet wt. pig heart; 14.51±2.11 nmol/g wet wt. in rat heart, and 4.35±0.71 nmol/g wet wt. in rat
skeletal muscle. These values were approximately 132% of those obtained using a separate procedure that measured total CoA
by HPLC after alkaline hydrolysis of the esters. The described method demonstrates the quantitation of individual acyl-CoA
species in muscle tissue. Therefore, it has a number of advantages in that it permits information to be obtained on the individual
molecular species under various nutritional and metabolic conditions. 相似文献
13.
Using the ratios of kinetic parameters, V/Km, the deacylation of different molecular species of 1-palmitoyl,2-acyl phosphatidylcholine
via microsomal phospholipase A2 (PLA2) was studied in liver tissue of thermally acclimated rainbow trout (Salmo gairdneri). In general, PLA2 from fish acclimated to cold temperatures showed an order of preference for the acyl moieties of 18∶1>18∶1>18∶2>18∶0. Trout
acclimated to warm temperatures generally preferred 18∶0 PC, but the actual order of preference depended on the temperature
of the assays and the presence of endogenous lipids in the enzyme preparation. At 5 C, the particulate (microsomal) enzyme
preferred 18∶0>18∶2>18∶1, but a lipid-free preparation of the enzyme preferred 18∶2>18∶0>18∶1. At 20 C, particulate enzyme
preferred 18∶1>18∶0>18∶2 but purified enzyme preferred 18∶0>18∶2>18∶1. Thus, assay temperature and the presence of microsomal
lipids had a greater effect on PLA2 from fish acclimated to warm temperatures than fish acclimated to cold temperatures. The substrate preference of PLA2 is discussed with reference to the previously observed changes in membrane fatty acid composition that occur with thermal
acclimation in rainbow trout. 相似文献
14.
The acylation of 1-palmitoyl-sn-glycerophosphocholine (1-16∶0-GPC) or 1-palmitoyl-sn-glycerophosphoethanolamine (1-16∶0-GPE) was measured using the microsomal fraction prepared from retinas of 14–15-day-old
chick embryos. Rates of incorporation of exogenously supplied fatty acids into diacyl-GPC were generally 5–7 times greater
than into diacyl-GPE. Substrate preferences for incorporation into diacyl-GPC and diacyl-GPE were, respectively, 18∶2>18∶3=20∶5>20∶4>18∶1>22∶6=18∶0
and 18∶2>22∶6≽18∶3=18∶0≽20∶4=18∶1>20∶5. The apparent selectivities were not consistent with the reported fatty acid compositions
of these lipid classes. The addition of partially purified fatty acid binding protein (FABP) to the reaction had no effect
either on overall rates of incorporation or on the substrate preference. When fatty acyl-CoA substrates were used, rates of
incorporation of the 18∶0 derivative were much higher than with the fatty acid, while rates with other fatty acyl-CoA were
similar to those with the respective fatty acid. Substrate preferences for CoA derivatives incorporated into diacyl-GPC were:
18∶0>20∶4>18∶2≽22∶6, and into diacyl-GPE: 20∶4=22∶6>18∶0>18∶2. Polyunsaturated fatty acyl CoA (PUFA-CoA) were thus favored
for incorporation into diacyl-GPE, and to a lesser extent into diacyl-GPC, a result that is consistent with composition data.
When purified FABP was added to the reactions, there was an increase in the incorporation of 18∶0-CoA and a decrease or no
change in the incorporation of PUFA-CoA. The deacylation/reacylation cycle thus appears to play a role in the modification
of phospholipid composition. The data are not consistent, however, with a role for FABP in directing PUFA toward membrane
lipid synthesis. 相似文献
15.
The molecular species composition of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS) from
white muscle, liver, retina and brain of cod (Gadus morhua) were determined by high-performance liquid chromatography of the respective 1,2-diacylglycerol 3,5-dinitrobenzoyl derivatives.
A minimum of 69 diacyl species was identified. In muscle and liver saturated fatty acid/polyunsaturated fatty acid (PUFA)
and monounsaturated fatty acid/PUFA molecular species were predominant, particularly 16∶0/20∶5 and 16∶0/22∶6 in PC, 16∶0/22∶6
and 18∶1/22∶6 in PE and 18∶0/22∶6 and 18∶1/22∶6 in PS. Didocosahexaenoyl species were major components of PC, PE and PS from
retina, comprising 29.3, 71.8 and 59.7% of the respective totals. Didocosahexaenoyl species were also abundant in PE and PS
from brain, accounting for 13.8 and 24.0% of the totals, respectively. DiPUFA species were important in muscle, totalling
21.2% in PC and 38.3% in PE. PC from all tissues had the largest amounts of species containing only saturated or monounsaturated
fatty acids, accounting for 59.8% of PC from brain, including 12.8% of 18∶1/24∶1 plus 24∶1/18∶1. 相似文献
16.
To test the possibility that dietary palmitic acid (16∶0) may be lithogenic, different fats were blended to exchange 18∶1
in olive oil with either 16∶0 in palm stearin, 12∶0+14∶0 in coconut oil, or 14∶0+16∶0 in butterfat. Dietary 18∶2 was held
constant at 1.2% energy (en) (with extra safflower oil as needed) in these four purified diets containing low fat (11% of
total energy) and 0.4% cholesterol. A fifth, high-fat diet provided 40% of the total energy as the 16∶0-rich blend. All hamsters
fed the low-fat, 16∶0-rich blend for six weeks developed cholesterol gallstones (8/8). Although the gallstone incidence was
lower for the 12∶0+14∶0-rich diet (5/8), the severity of stone formation in affected hamsters was equal to that in the low-fat,
16∶0-rich group. Mucin accumulation in gallbladder bile was often associated with cholesterol gallstones in diets containing
16∶0, but was minimal in 18∶1-rich and 12∶0+14∶0-rich groups. Neither the lithogenic index (all>1.0), plasma lipids, nor liver
cholesterol was a selective predictor of stone formation. The high-fat, 16∶0-rich diet actually decreased cholesterol stone
incidence (3/8) and severity, but yielded a high incidence of pigment stones (5/8). Thus, saturated fat and 16∶0per se were not responsible for the exaggerated lithogenesis. Because the antilithogenic 18∶1-rich diet also normalized the 18∶2
intake (1.2% en) relative to previous butter diets (0.3% en), the potential importance of essential fatty acids (EFA) deficiency
in the model was tested in a second study by feeding graded amounts of 18∶2 (0.3, 0.6, 0.9, and 1.2% en) as safflower oil
in four low-fat, butter-rich diets (11% en as fat) without alleviating gallstone incidence or severity. These studies indicate
that substitution of 18∶1 for saturated fatty acids in low-fat diets reduces gallstone formation without affecting the lithogenic
index. Furthermore, intake of 18∶2 at or below the EFA requirement does not appear to be a major factor in this model. 相似文献
17.
Satyesh C. Pakrashi Pradeep K. Duffa Basudeb Achari Suniti Misra Amalesh Choudhury Subhashis Chattopadhyay Amitabha Ghosh 《Lipids》1989,24(5):443-447
Total lipids from hepatopancreas of the horseshoe crabs,Tachypleus gigas andCarcinoscorpius rotundicauda, obtained in 7.6 and 3.3% wet weight respective yields, were fractionated by various chromatographic techniques and identified
by gas-liquid chromatography and spectroscopic methods. Fatty acid-containing lipids were rich in 16∶0 (8.0–25%), 18∶1ω9 (6.9–22%)
and 18∶2ω6 (6.8–18.5%); appreciable amounts of 16∶1ω7, 18∶3ω3, 20∶5ω3 and 22∶6ω3 were also present. The level of 26∶0 in the
hydrocarbon fractions was unusually high (64 and 68%). Carbon chain lengths of major wax esters were 44, 46 and 48 forT. gigas and 38, 40 and 42 forC. rotundicauda. 1-O-Alkyl diglycerides were 7.2 and 9.1% of the total lipids in the two species and contained 14∶0(20%), 16∶0(60%) and 18∶0(20%)
alkyl chains along with a relatively higher percentage (32–35%) of saturated fatty acids. High levels of cholesterol (>50%
of total sterol) in the free and combined state were encountered in both samples, phospholipid contents being 40 and 35%,
respectively, and contained highest levels of unsaturated fatty acids. 相似文献
18.
Masaki Kaneniwa Song Miao Chunhong Yuan Haruka Lida Yutaka Fukuda 《Journal of the American Oil Chemists' Society》2000,77(8):825-831
The lipid and fatty acid composition of muscle of 10 species of freshwater fish obtained from a market of Shanghai City was
examined. Total lipids (TL) ranged over 0.9–4.7% of muscle for all samples. The content of triacylglycerol (TG) in muscle
ranged over 0.2–3.4% and that of polar lipids (PL) was 0.5–1.3%. Differences of TL content were dependent on TG contents.
The predominant important fatty acids (>10% of the total fatty acids in TL) were 16∶0 and 18∶1n−9 with some 16∶1n−7, 18∶2n−6,
and 22∶6n−3. The polyunsaturated fatty acids (PUFA) content was 10.2–43.4%, and especially Chinese sea bass contained above
20% of 22∶6n−3 in the total fatty acids. There were higher levels of PUFA such as 20∶5n−3 and 22∶6n−3 in PL than in neutral
lipids. Muscle of the silver carp was stored at 20°C, and changes of lipid classes during storage were examined. Free fatty
acids increased, and PL decreased during storage. This phenomenon was inhibited by heating the muscle, suggesting that lipid
hydrolysis by phospholipase occurred in silver carp muscle. 相似文献
19.
Molecular architecture and biophysical properties of phospholipids during thermal adaptation in fish: An experimental and model study 总被引:1,自引:0,他引:1
Elfrieda Fodor Richard H. Jones Csaba Buda Klara Kitajka Indranil Dey Tibor Farkas 《Lipids》1995,30(12):1119-1126
Phospholipids from livers of carps (Cyprinus carpio L.) adapted to winter (5°C) and summer (25°C) temperatures were isolated, and the fatty acid composition of total phospholipids,
as well as molecular species composition of diacyl phosphatidylcholines and ethanolamines, were determined. Order parameter
of 5-doxyl stearic acid and steady-state fluorescence anisotropy of different anthroyloxy fatty acids—[2-, 12(N-9-anthroyloxy)stearic acid and 16(N-9-anthroyloxy)palmitic acid—embedded in native and synthetic (16∶0/16∶0, 16∶0/22∶6, 18∶0/22∶6, 18∶1/22∶6, 20∶4/20∶4, 22∶6/22∶6
phosphatidylcholines and 16∶0/18∶1, 18∶1/22∶6 phosphatidylethanolamines) phospholipid vesicles was also determined between
−30 and 30°C and 5 and 30°C, respectively. There is an accumulation of 1-monoenoic, 2-polyenoic diacyl phosphatidylcholine
and ethanolamine with a concomitant reduction of 1-stearoyl,2-docosahexaenoyl species in the cold-adapted state. Despite a
30% accumulation of long-chain polyunsaturated fatty acids in phospholipids in cold, there is only a 5°C downshift in the
solid-gel to liquid-crystalline phase transition temperature (−8 vs. −13°C). Vesicles from total phospholipids of cold-adapted
fish proved to be more disordered in all segments than from the warmadapted ones when assayed using 2,12-(N-9-anthroyloxy)stearic and 16-(N-9-anthroyloxy)palmitic acid. Vesicles made from purified phosphatidylcholines showed the same pattern, but they were more
disordered than the corresponding total phospholipids. This could be modelled using mixed phospholipid vesicles made of synthetic
16∶0/22∶6 phosphatidylcholine (75%) and either 18∶1/22∶6 phosphatidylethanolamine (25%) vs. 16∶0/18∶1 phosphatidylethanolamine
(25%) and comparison of the anisotropy parameters of 100% 16∶0/22∶6 and 100% 18∶1/22∶6 phosphatidylcholine vesicles. Mixing
either 16∶0/18∶1 (25%) or 18∶1/22∶6 (25%) phosphatidylethanolamines to 18∶0/22∶6 (75%) phosphatidylcholine shifted down or
up, respectively, the transition temperature of vesicles compared to 100% 18∶0/22∶6 vesicles assayed by electron spin resonance
spectroscopy using 5-doxylstearic acid. It is concluded that it is not the gross amount of long-chain polyunsaturated fatty
acids in phospholipids, but rather their specific combination withcis Δ9 monounsaturated fatty acids in the positionsn-1, especially in phosphatidylethanolamines, that is important in determining the physical properties of biomembranes in relation
to adaptational temperature. 相似文献
20.
Isabelle Delton-Vandenbroucke Maureen B. Maude Huiming Chen Gustavo D. Aguirre Gregory M. Acland Robert E. Anderson 《Lipids》1998,33(12):1187-1193
Dogs were born to mothers fed commercial diets low or enriched in n-3 fatty acids and raised on those diets until they were
about 50 d old. Retinas were removed, lipids were extracted, and total phospholipids were anlyzed for fatty acid and molecular
species composition. Animals from the low n-3 group had significantly lower retinal levels of 22∶6n-3 and higher levels of
n-6 fatty acids, especially 20∶4n-6 and 22∶5n-6. There was no difference in the retinal levels of 18∶2n-6, and only small
differences were found in saturated and monounsaturated fatty acids. The most dramatic differences in molecular species occurred
in 22∶6n-3-22∶6n-3 (4.7 vs. 0.8%) and 18∶0-22∶6n-3 (27.6 vs. 14.4%); total molecular species containing 22∶6n-3 were significantly
lower in the low n-3 group (45.5 vs. 24.0%). Molecular species containing 20∶4n-6 and 22∶5n-6 were greater in the low n-3
animals (13.0 vs. 25.7%), as were molecular species containing only saturated and monounsaturated fatty acids (40.8 vs. 35.4%).
These results show that modest differences in the amount of n-3 fatty acids in the diets of dogs can have profound effects
on the fatty acid and molecular species composition of their retinas. 相似文献